Device for maintaining grass fields

ABSTRACT

The invention relates to a device for maintaining grass fields, provided with a frame ( 1 ) movable along a ground surface, supporting on one or more support wheels ( 2 ), a gearbox with power take-offs ( 5 ), a steering handle ( 11 ), a drive motor ( 10 ), and with exchangeable working attachments which can be fixedly connected to the device and another support wheel ( 7 ) on one side adjacently of this working attachment which can be connected fixedly, pivotally or for active steering to the frame with a supporting arm ( 8 ) which is adjustable in position and lockable.

This application is a 371 of PCT/NL01/00487 filed Jun. 28, 2001.

The invention relates to a device for maintaining grass fields, furtherreferred to as lawns, wherein, as seen in the direction of travel, nosupport wheels which first rest on the surface for working are placed inthe projected working surface for an exchangeable working attachmentwhich can be fixedly coupled to the frame.

A lawn requires many diverse maintenance operations. In addition tomowing in the horizontal plane, mowing in the vertical plane, cuttingedges, adding fertilizer, removing leaves and so on can be envisagedhere.

Maintenance machines are known for all these operations. It is sometimespossible to perform a plurality of operations with one basic device,because these devices have exchangeable attachments.

For an optimal level working it is of great importance that the device,particularly the working attachment, is held at a fixed, stable,adjustable height above the surface for working. The position of thesupport wheels is essential herein. These support wheels serve to holdthe device in balance and support it such that the working takes placeoptimally even in the case of uneven lawns. Known machines thereforeusually have a plurality of support wheels. An optimal support isobtained by three support wheels, although more support wheels are oftenadded so as to enable better following of an uneven surface. It is oftenunavoidable herein that one or more support wheels are positioned in theprojected working surface in front of the working attachment. This hasgreat drawbacks, for instance when grass is mown in the horizontalplane. This is because the grass in front of the working attachment isfirst flattened by a support wheel, whereafter the mowing attachment canno longer mow this strip. After a time this strip will recover, therebyresulting in an unevenly mown, irregular grass field.

Devices are also known with a support wheel on both sides adjacently ofthe working attachment. These support wheels then lie adjacently of theprojected working surface in front of the working attachment. The grassis then not flattened directly, but indirectly. If a support wheel ispositioned adjacently of the working attachment on both sides of theworking attachment, one of the two will then always rest on the as yetunworked lawn. Nor is it then possible to work close to lawn edges orobstacles, since a support wheel supports adjacently of the workingattachment.

The present invention has for its object to provide an improved supportfor the support wheels, wherein the above stated drawbacks are obviated.

The invention provides for this purpose a device according to claim 1. Asupport wheel is herein preferably connected to the frame with asupporting arm on one side adjacently of the fixedly mountable workingattachment, wherein the position is determined such that the wholedevice, including a fixedly connected exchangeable working attachment,does not tilt.

The support wheel adjacently of the working attachment can be fixedly orpivotally connected to the supporting arm. If it is connected pivotally,the whole device can be passively steered by exerting a lateral force onthe steering handle of the device, whereby the support wheel will pivot.

An improved steering is obtained if the support wheel adjacently of theworking attachment is made actively steerable. The support wheelpivotable in the horizontal plane can be connected for this purpose tothe likewise pivotable steering handle by means of a rod system. By nowpivoting the steering handle the support wheel adjacently of the workingattachment will pivot to the same degree. The device can hereby beactively steered during working of the lawn and transport, without thecharacter of the support being changed.

The support wheel adjacently of the working attachment is connected tothe frame by means of a supporting arm. If this supporting arm ismounted on the frame for rotation in the vertical plane, the position ofthe frame relative to the supporting arm can be changed using alength-adjustable guide arm. If the position of the frame changes, thedistance of the mounted working attachment relative to the supportsurface will also change.

By herein mounting a catch on the frame with a hook-in element on thesupporting arm, the frame can be fixedly connected in raised position tothe supporting arm. This is a great advantage if it is desired to lockthe frame with working attachment in transport position. The workingattachment is hereby held clear of the underlying support surface onwhich the support wheels rest.

Since the device has only one support wheel adjacently of theexchangeable attachment, the exchangeable working attachment canprotrude outside the frame on the opposite side of the support wheel.Obstacles such as support wheels and the like are after all not situatedthere.

Because the space in front of the frame and adjacently of the supportwheel adjoining the surface for working is further free of anyobstacles, diverse working attachments can be mounted. These workingattachments are centred by means of dowel pins. If working attachmentshave to be driven, they can be connected to the power take-offs, whichcan be coupled.

The present invention will be further elucidated on the basis of thenon-limitative embodiment shown in the following figures. Herein:

FIG. 1 shows a perspective view of the device without a mounted workingattachment.

FIG. 2 shows a top view of the device, once again without a workingattachment.

FIG. 3 is a side view on the side of the adjacent support wheel next tothe working attachment.

FIG. 4 is a side view as in FIG. 3, but now with the device locked intransport position.

FIG. 5 shows a perspective view as in FIG. 1, but now provided with afixedly mounted exchangeable working attachment.

FIG. 1 shows a maintenance machine for lawns, comprising a frame 1 underwhich are mounted support wheels 2. These support wheels can be drivenfrom gearbox 9. This drive can be coupled by means of control lever 14.A subsequent support wheel 7 is situated adjacently of the projectedworking surface 15. Support wheel 7 is connected to supporting arm 8 bymeans of a pivotable arm 6. Steering handle 11 is connected pivotally onits longitudinal axis to frame 1. Via rod system 4 the support wheel 7is actively steered by steering handle 11. A number of power take-offs 5are arranged in gearbox 9. These power take-offs can be coupled to drivemotor 10 by means of control lever 12. Centring pins 3 are furtherarranged so that exchangeable working attachments can be mounted quicklyand, if necessary, driven by means of one of the power take-offs 5.

FIG. 2 further shows that support wheel 7 can be actively steered bysteering handle 11. If the steering handle is pivoted through an angleR, support wheel 7 will pivot through an angle R1 via rod system 4.Pivoting of the steering handle through an angle L produces a deflectionof L1 of support wheel 7.

FIG. 3 shows a side view of support wheel 7, mounted on supporting arm 8via a pivot arm 6. This supporting arm is further mounted on frame 1 forpivoting in the vertical plane by means of a pin 32. A length-adjustableguide arm 31 is then arranged which allows frame 1 to support on thesupporting arm via point 33, by means of adjusting knob 30. By nowaltering the length of the guide arm by means of 30, distance H willchange. The distance H has a direct relation to the distance above thesupport surface 34 of a working attachment for mounting.

In FIG. 4 is shown that the supporting arm can be locked in sportposition using catch 42 and hook-in element 41. Catch 42 is operated bya control lever (not further shown) on the steering handle. The distanceH1 is essentially greater than H in FIG. 3. The working attachment isnow therefore held well above support surface 34, whereby transport cantake place in simple manner. The geometry of rod assembly 4 is designedsuch that steering by means of steering handle 11, as shown in FIG. 2,is also possible in the transport position of FIG. 4.

FIG. 5 finally shows how a possible working attachment can be fixedlyconnected to the device in front of the frame and adjacently of supportwheel 7 by means of the dowel pins 3, which are not all visible, and thelocking which is not further shown. The driven working attachment 50 isa mowing device for mowing grass in the horizontal plane.

1. A device for maintaining grass lawns, comprising: a frame movablealong a ground surface, a frame support wheel on either side under thisframe, a gearbox protruding forward as seen in the travel direction,said gearbox including a plurality of power take-offs, a steering handleconnected to the frame, a drive motor on the same side as the gearbox,an exchangeable working attachment fixedly mountable on the front partof the frame as seen in the travel direction, said attachmentconnectable to at least one of said power take-offs, a support wheel onthe side adjacent of the working attachment, wherein the support wheelis connected by a supporting arm to the frame on one side adjacently ofthe exchangeable working attachment such that the working device,including the working attachment, does not tilt.
 2. A lawn maintainingdevice of claim 1, wherein the support wheel adjacently of the workingattachment is pivotally connected to the supporting arm.
 3. A lawnmaintaining device of claim 1 wherein the support wheel adjacent to theworking attachment is actively steerable.
 4. A lawn maintaining deviceof claim 1, wherein the support wheel can be actively steered by thesteering handle.
 5. A lawn maintaining device of claim 1 wherein thesupporting arm is connected to the frame for pivoting in the verticalplane.
 6. A lawn maintaining device of claim 5, wherein the supportingarm rotatable in the vertical plane is connected to the frame with alength-adjustable guide arm, whereby the position of the supporting armcan be changed.
 7. A lawn maintaining device of claim 5, wherein theframe can be fixedly connected to the supporting arm in raised positionto lock the device with the working attachment in transport position. 8.A lawn maintaining device of claim 1, wherein the space in front of theframe as seen in the travel direction, and opposite the support wheelplaced adjacently of the exchangeable working attachment for mounting,is free of any obstacles of the frame.
 9. A lawn maintaining device ofclaim 1, wherein the exchangeable working attachment can protrudeoutside the frame on the opposite side of the support wheel connected tothe supporting arm.
 10. A lawn maintaining device of claim 1, whereindifferent working attachments can be connected to the gearbox by meansof dowel pins and a locking device.
 11. A lawn maintaining device ofclaim 1, wherein the individually mountable working attachements aredrivable by means of at least one power take-off.